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Seasonal variation in major depressive episode prevalence in Canada

Published online by Cambridge University Press:  11 January 2016

S. B. Patten*
Affiliation:
Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada Mathison Centre for Mental Health Research & Education, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
J. V. A. Williams
Affiliation:
Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada
D. H. Lavorato
Affiliation:
Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada
A. G. M. Bulloch
Affiliation:
Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada Mathison Centre for Mental Health Research & Education, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
K. M. Fiest
Affiliation:
Department of Internal Medicine (Neurology), University of Manitoba, Winnipeg, Manitoba, Canada
J. L. Wang
Affiliation:
Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada Mathison Centre for Mental Health Research & Education, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
T. T. Sajobi
Affiliation:
Department of Community Health Sciences and Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
*
*Address for correspondence: S. B. Patten, Department Community Health Sciences, 3rd Floor TRW Building, University of Calgary, 3280 Hospital Drive NW, Calgary, Alberta, AB T2N 4Z6, Canada. (Email: patten@ucalgary.ca)

Abstract

Background.

The purpose of this paper is to describe variation, over the months of the year, in major depressive episode (MDE) prevalence. This is an important aspect of the epidemiological description of MDE, and one that has received surprisingly little attention in the literature. Evidence of seasonal variation in MDE prevalence has been weak and contradictory. Most studies have sought to estimate the prevalence of seasonal affective disorder using cut-points applied to scales assessing mood seasonality rather than MDE. This approach does not align with modern classification in which seasonal depression is a diagnostic subtype of major depression rather than a distinct category. Also, some studies may have lacked power to detect seasonal differences. We addressed these limitations by examining the month-specific occurrence of conventionally defined MDE and by pooling data from large epidemiological surveys to enhance precision in the analysis.

Method.

Data from two national survey programmes (the National Population Health Survey and the Canadian Community Health Survey) were used, providing ten datasets collected between 1996 and 2013, together including over 500,000. These studies assessed MDE using a short form version of the Composite International Diagnostic Interview (CIDI) for major depression, with one exception being a 2012 survey that used a non-abbreviated version of the CIDI. The proportion of episodes occurring in each month was evaluated using items from the diagnostic modules and statistical methods addressing complex design features of these trials. Overall month-specific pooled estimates and associated confidence intervals were estimated using random effects meta-analysis and a gradient was assessed using a meta-regression model that included a quadratic term.

Results.

There was considerable sampling variability when the month-specific proportions were estimated from individual survey datasets. However, across the various datasets, there was sufficient homogeneity to justify the pooling of these estimated proportions, producing large gains in precision. Seasonal variation was clearly evident in the pooled data. The highest proportion of episodes occurred in December, January and February and the lowest proportions occurred in June, July and August. The proportion of respondents reporting MDE in January was 70% higher than August, suggesting an association with implications for health policy. The pattern persisted with stratification for age group, sex and latitude.

Conclusions.

Seasonal effects in MDE may have been obscured by small sample sizes in prior studies. In Canada, MDE has clear seasonal variation, yet this is not addressed in the planning of services. These results suggest that availability of depression treatment should be higher in the winter than the summer months.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 2016 

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References

Akhter, A, Fiedorowicz, JG, Zhang, T, Potash, JB, Cavanaugh, J, Solomon, DA, Coryell, WH (2013). Seasonal variation of manic and depressive symptoms in bipolar disorder. Bipolar Disorders 15, 377384.Google Scholar
American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders (DSM-5). American Psychiatric Publishing: Washington, DC.Google Scholar
Cobb, BS, Coryell, WH, Cavanaugh, J, Keller, M, Solomon, DA, Endicott, J, Potash, JB, Fiedorowicz, JG (2014). Seasonal variation of depressive symptoms in unipolar major depressive disorder. Comprehensive Psychiatry 55, 18911899.Google Scholar
Kerr, DC, Shaman, J, Washburn, IJ, Vuchinich, S, Neppl, TK, Capaldi, DM, Conger, RD (2013). Two longterm studies of seasonal variation in depressive symptoms among community participants. Journal of Affective Disorders 151, 837842.CrossRefGoogle ScholarPubMed
Kessler, RC, Ustun, TB (2004). The world mental health (WMH) survey initiative version of the world health organization (WHO) composite international diagnostic interview (CIDI). International Journal of Methods in Psychiatric Research 13, 83121.Google ScholarPubMed
Kessler, RC, Andrews, G, Mroczek, D, Ustun, B, Wittchen, HU (1998). The world health organization composite international diagnostic interview short-form (CIDI-SF). International Journal of Methods in Psychiatric Research 7, 171185.Google Scholar
Magnusson, A (2000). An overview of epidemiological studies on seasonal affective disorder. Acta Psychiatrica Scandinavica 101, 176184.Google Scholar
Mersch, PP, Vastenburg, NC, Meesters, Y, Bouhuys, AL, Beersma, DG, Van Den Hoofdakker, RH, Den Boer, JA (2004). The reliability and validity of the seasonal pattern assessment questionnaire: a comparison between patient groups. Journal of Affective Disorders 80, 209219.Google Scholar
Michalak, EE, Murray, G, Wilkinson, C, Dowrick, C, Lasa, L, Lehtinen, V, Dalgard, OS, Ayuso-Mateos, JL, Vazquez-Barquero, JL, Casey, P, the ODIN Group (2004). Estimating depression prevalence from the beck depression inventory: is season of administration a moderator? Psychiatry Research 129, 99106.Google Scholar
Oyane, NM, Bjelland, I, Pallesen, S, Holsten, F, Bjorvatn, B (2008). Seasonality is associated with anxiety and depression: the Hordaland health study. Journal of Affective Disorders 105, 147155.CrossRefGoogle ScholarPubMed
Patten, SB, Wang, JL, Williams, JV, Currie, S, Beck, CA, Maxwell, CJ, El-Guebaly, N (2006). Descriptive epidemiology of major depression in Canada. Canadian Journal of Psychiatry 51, 8490.Google Scholar
Patten, SB, Williams, JVA, Lavorato, D, Fiest, KM, Bulloch, AGM, Wang, JL (2014). The prevalence of major depression is not changing. Canadian Journal of Psychiatry 60, 3134.CrossRefGoogle Scholar
Rosenthal, NE (2009). Issues for DSM-V: seasonal affective disorder and seasonality. American Journal of Psychiatry 166, 852853.Google Scholar
Rosenthal, NE, Sack, DA, Gillin, JC, Lewy, AJ, Goodwin, FK, Davenport, Y, Mueller, PS, Newsome, DA, Wehr, TA (1984). Seasonal affective disorder. A description of the syndrome and preliminary findings with light therapy. Archives of General Psychiatry 41, 7280.Google Scholar
Sakamoto, K, Nakadaira, S, Kamo, K, Kamo, T, Takahashi, K (1995). A longitudinal follow-up study of seasonal affective disorder. American Journal of Psychiatry 152, 862868.Google ScholarPubMed
Schwartz, PJ, Brown, C, Wehr, TA, Rosenthal, NE (1996). Winter seasonal affective disorder: a follow-up study of the first 59 patients of the National Institute of Mental Health Seasonal Studies Program. American Journal of Psychiatry 153, 10281036.Google Scholar
Stata Corporation (2013). Stata (version 13). College Station: TX, Stata Corporation.Google Scholar
Statistics Canada (2011). Canadian Community Health Survey – Annual Component (CCHS). Statistics Canada: Ottawa. Retrieved 24 April 2015 from http://www.statcan.gc.ca/cgi-bin/imdb/p2SV.pl?Function=getSurvey&SDDS=3226&lang=en&db=imdb&adm=8&dis=2 Google Scholar
Statistics Canada (2013). National Population Health Survey – Household Component – Cross-Sectional (NPHS). Retrieved 30 December 2013 from http://www23.statcan.gc.ca/imdb/p2SV.pl?Function=getSurvey&SDDS=3236&lang=en&db=imdb&adm=8&dis=2 Google Scholar
Suhail, K, Cochrane, R (1998). Seasonal variations in hospital admissions for affective disorders by gender and ethnicity. Social Psychiatry & Psychiatric Epidemiology 33, 211217.Google Scholar
Thompson, C, Raheja, SK, King, EA (1995). A follow-up study of seasonal affective disorder. British Journal of Psychiatry 167, 380384.Google Scholar
Tri-Council Panel on Ethics (2014). TCPS 2—2nd edition of Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans. Panel on Research Ethics: Ottawa. Retrieved 24 April 2015 from http://www.pre.ethics.gc.ca/eng/policy-politique/initiatives/tcps2-eptc2/Default/ Google Scholar
Tuuanainen, A, Kripke, DF, Endo, T (2004). Light therapy for non-seasonal depression. Cochrane Library, Art. No.: CD004050. DOI: 10.1002/14651858.CD004050.pub2.Google Scholar
Winthorst, WH, Post, WJ, Meesters, Y, Penninx, BW, Nolen, WA (2011). Seasonality in depressive and anxiety symptoms among primary care patients and in patients with depressive and anxiety disorders; results from the Netherlands study of depression and Anxiety. BMC Psychiatry 11, 198.Google Scholar
Yang, AC, Huang, NE, Peng, CK, Tsai, SJ (2010). Do seasons have an influence on the incidence of depression? The use of an internet search engine query data as a proxy of human affect. PLoS ONE 5, e13728.Google Scholar
Young, SN (2011). Bright light for nonseasonal depression? Journal of Psychiatry & Neuroscience 36, E37E38.CrossRefGoogle ScholarPubMed